Shoulder pain following stroke is a major rehabilitation problem affecting approximately 60% of moderate to severely impaired stroke survivors. The investigative team recently demonstrated the efficacy of percutaneous intramuscular (IM) electrical stimulation (ES) in treating post-stroke shoulder pain. However, only those individuals enrolled within 18-mo of their stroke experienced enduring treatment effect. Participants enrolled after this 18-mo period experienced significant pain reduction at the end of treatment, but the therapeutic benefit did not persist in the long-term. This population may benefit from a fully implanted ES system. A phase I feasibility trial is proposed to demonstrate the safety and initial efficacy of a Two-stage Implanted ES system for the treatment of shoulder pain for those who are greater than 18-mo from stroke. During the Trial Stage, stroke survivors who experience short-term benefit from percutaneous IM ES will be identified. During the Implant Stage, these participants will receive the fully implanted ES system and be followed for 6-mo. Outcomes measures will include the Brief Pain Inventory question 12, radiographic glenohumeral subluxation, Fugl-Meyer Motor Assessment and the Arm Motor Ability Test. PUBLIC HEALTH RELEVANCE: Shoulder pain following stroke is a major rehabilitation problem affecting approximately 60% of all moderate to severely impaired stroke survivors, and is associated with poor recovery, impaired activities of daily living and reduced quality of life. Shoulder pain among chronic stroke survivors is especially difficult to treat. This project will evaluate the effectiveness of a novel two-stage implanted electrical stimulation system for treating shoulder pain among chronic stroke survivors.